The invention relates to a device for recording myoelectric activity of a human organ and, more particularly, to a catheter structure having electrodes that are delivered into the human organ to record myoelectric activity of the organ.
Gastric myoelectrical activity comprises slow waves or pacesetter potentials and, action potential activity. The recording or measurement of gastric pacesetter potentials is presently accomplished with either electrodes sewn to the stomach serosa, an invasive procedure that requires surgery, or with electrodes placed on the abdominal surface. The electrodes placed on the abdominal surface record electrogastrograms or EGGs. These non-invasive recordings indicate the presence of normal 3-cpm activity at baseline and in response to a variety of foods or drugs.
Patients with unexplained dyspepsia symptoms or unexplained nausea and vomiting often have no obvious cause for these symptoms. No peptic ulcer disease, reflux disease or gallbladder abnormalities are found. Gastric dysrhythmias are frequent pathophysiological findings in these patients. Gastric dysrhythmias are termed bradygastrias (1.0-2.5 cpm) and tachygastrias (3.7-10.0 cpm). These gastric dysrhythmias have been defined in many different patient groups where dyspepsia symptoms are present. They have been recorded by serosal, mucosal and cutaneous electrode recordings.
The disadvantage of the EGG is that the signal must pass through the abdominal wall and adipose tissue before it is recorded. The EGG signal is also subject to movement artifact (errors). The disadvantage of the placement of electrodes on the serosa of the stomach is that surgical procedures are required that vary from a laparotomy to laparoscopic surgery. Furthermore, electrode wires must be brought to the surface through wounds in the abdominal wall. The disadvantage of the mucosal electrodes is that they are clipped onto the mucosa and frequently become dislodged during gastric contractions.
Accordingly, there is a need to provide a catheter structure that can be placed into the human organ under direct vision via an endoscope to record myoelectric activity of the organ.
An object of the invention is to fulfill the need referred to above. In accordance with the principles of the present invention, this objective is achieved by providing a catheter structure including an elongated tube structure having distal and proximal ends and an axis. Electrodes are associated with the tube structure and are constructed and arranged to be moved from a retracted position substantially within the tube structure to an extended position extended directly outwardly from the distal end of the tube structure and generally in the direction of the axis. The electrodes are constructed and arranged to obtain signals relating to myoelectrical activity of an intra-abdominal organ. Actuating structure is operatively associated with the electrodes to move the electrodes between the extended and retracted positions.
In accordance with another aspect of the invention, a method is provided for obtaining myoelectric activity from an intra-abdominal body organ having an internal cavity and a lining. The method provides catheter structure including an elongated tube structure having distal and proximal ends and an axis. Electrodes are associated with the tube structure and are constructed and arranged to be moved from a retracted position substantially within the tube structure to an extended position extended directly outwardly from the distal end of the tube structure and generally in the direction of the axis. The electrodes are constructed and arranged to obtain signals relating to myoelectrical activity of an intra-abdominal organ of a patient. Actuating structure is operatively associated with the electrodes to move the electrodes between the extended and retracted positions. The tube structure is inserted into the internal cavity of the organ, with the electrodes being in a retracted position with respect to the distal end of the tube structure. The actuating structure is moved to move the electrodes to the extended position to impinge on the lining of the organ. A respiration sensor is provided to monitor respiration of the patient. Signals from the electrodes indicative of myoelectrical activity of the organ are recorded. In addition, signals from the respiration sensor are recorded to determine when artifact occurs.
Other objects, features and characteristics of the present invention, as well as the methods of operation and the functions of the related elements of the structure, the combination of parts and economics of manufacture will become more apparent upon consideration of the following detailed description and appended claims with reference to the accompanying drawings, all of which form a part of this specification.